1. Technical Field of the Invention
This invention relates to radio telecommunication systems and, more particularly, to a method of delivering data and real-time media such as voice to a mobile terminal utilizing a packet-switched network and a circuit-switched network.
2. Description of Related Art
The telecommunications industry is currently in the process of developing a third generation (3G) all Internet Protocol (IP) radio telecommunications network that will be capable of simultaneous delivery of non-real-time packet data and real-time media such as voice. However, before 3G networks are deployed, it is anticipated that there will be a first phase of development during which real-time services such as voice will go through second generation (2G) circuit-switched networks while non-real-time packet data will go through networks such as the General Packet Radio Service (GPRS) or Enhanced Data Rates for GSM Evolution (EDGE) networks. Initially, the EDGE networks will be non-real-time networks. In the next phase, real-time EDGE services will be introduced.
While Class-A mobile terminals can access both data networks and circuit-switched networks at the same time, Class-B mobile terminals are limited to accessing one type of network at a time. Therefore in the first phase of development, a Class-B mobile terminal will be able to access real-time services such as voice from a circuit-switched network, or will be able to access non-real-time data services from an EDGE network, but cannot access both networks simultaneously. There is some level of coordination between the two types of networks for paging and location updating, but there is no way to associate a voice call in the circuit-switched network with a data session in the packet-switched network. Therefore, it is not possible to offer services in which there is interaction between the packet-switched and circuit-switched services.
It would be advantageous to have a method of delivering data and real-time media such as voice to a mobile terminal during the development of 3G networks that provides the appearance to the users that the services are both real-time. The present invention provides such a method.